bool MonomialHashTable<ValueType>::find_or_insert(value m, value &result)
// return true if the value already exists in the table.
// otherwise, result is set to the new value.
{
long hashval = HASHVALUE(m) & hashmask;
if (!hashtab[hashval])
{
// No entry is there. So, we insert it directly.
hashtab[hashval] = m;
result = m;
count++;
if (count > threshold) grow();
return false;
}
else
{
// Something is there, so we need to find either this value,
// or a free spot, whichever comes first.
long mhash = HASHVALUE(m);
value *hashtop = hashtab + size;
long run_len = 1;
for (value *i = hashtab + hashval; ; i++, run_len++)
{
if (run_len > max_run_length)
max_run_length = run_len;
if (i == hashtop) i = hashtab;
if (!(*i))
{
// Spot is empty, so m is a new value
*i = m;
result = m;
count++;
if (count > threshold) grow();
return false;
}
if (HASHVALUE(*i) == mhash)
{
monequal_count++;
if (MONOMIAL_EQUAL(m, *i))
{
monequal_count++;
result = *i;
return true;
}
monequal_fails++;
}
nclashes++;
}
}
}
void decrease_refcount(void *pointer)
{
int i=HASHVALUE(pointer);
RefElem **re=&(hash_table[i]);
if (!pointer) return;
while (*re && (*re)->pointer!=pointer)
re=&(*re)->next;
if (*re) {
(*re)->count--;
LOG_MESSAGE("setting counter to %i\n", (*re)->count);
if (!(*re)->count) {
RefElem *h;
LOG_MESSAGE("counter at 0, freeing %x\n", pointer);
h=*re;
if (h->freefunc) {
(*h->freefunc)(pointer);
}
*re = h->next;
FreeList_free(&refelems, h);
}
} else {
LOG_MESSAGE("No reference counting on supplied pointer %x\n",pointer);
refcount_break(16);
}
}
void MonomialHashTable<ValueType>::insert(value m)
{
long hashval = HASHVALUE(m) & hashmask;
while (hashtab[hashval]) {
hashval++;
nclashes++;
if (hashval == size)
hashval = 0;
}
hashtab[hashval] = m;
count++;
if (count > threshold) grow();
}
void increase_refcount(void *pointer, void (*freefunc)(void*))
{
int i=HASHVALUE(pointer);
RefElem *re= hash_table[i];
if (!pointer) return;
while (re && re->pointer!=pointer) re=re->next;
if (re) {
re->count++;
LOG_MESSAGE("setting counter to %i\n", re->count);
} else {
LOG_MESSAGE("new pointer %x\n", pointer);
re=FreeList_malloc(&refelems);
re->next=hash_table[i];
re->pointer=pointer;
re->count=1;
re->freefunc=freefunc;
hash_table[i]=re;
}
}
